S100A6上调人乳腺癌细胞系MCF-7中β-catenin及其机制

摘要

目的 探讨钙细胞周期蛋白S100A6对人乳腺癌细胞系MCF-7中β-catenin的影响及其机制.方法 分别用表达S100A6及其siRNA的重组腺病毒AdS100A6与AdsiS100A6处理MCF-7细胞,RT-PCR、Western blot和免疫细胞化学检测β-catenin、E-钙黏蛋白(E-cadherin)和磷酸化糖原合酶激酶3β(p-GSK3β)表达或分布的变化.结果 在MCF-7细胞中,S100A6可以上调β-catenin的蛋白表达水平(P＜0.01),但对其mRNA表达无显著性影响；S100A6对E-cadherin的mRNA表达、蛋白质表达水平及分布均无显著性影响；S100A6可以提高β-catenin降解复合体的主要成员GSK3β磷酸化水平(P＜0.01).结论 S100A6上调β-catenin的可能机制是通过促进GSK3β磷酸化失活,而不是通过调节E-cadherin实现的.%Objective To investigate the impact of S100A6 on β-catenin and its molecular mechanism in human breast cancer cell line MCF-7.Methods MCF-7 cells were infected by recombinant adenoviruses carrying human S100A6 and its siRNA gene,AdS100A6 and AdsiS100A6 respectively.RT-PCR,Western blot and immunocytochemistry were used to detect the expression and/or distribution of β-catenin,E-cadherin and p-GSK3β.Results In MCF-7 cells,S100A6 increased the protein level of β-catenin(P ＜0.01),but no significant difference in transcriptional level of β-catenin between S100A6 group and control group(GFP group)(P ＞0.05) ; The mRNA,protein level and distribution of E-cadherin had no significant difference between S100A6 group and control group(P ＞0.05) ; S100A6 increased phosphorylation of GSK3β(P ＜0.01).Conclusions S100A6 may upregulate β-catenin by promoting phosphorylation of GSK3β,rather than via effect on E-cadherin.